The width of crop and forage mowing machines, such as mower-conditioners, self-propelled windrowers, and the like have been increasing in order to form sufficiently large windrows of crop to meet the capacity of modern balers and forage harvesters. These wider mowing machines have presented the challenge to designers of how to converge the mowed crop. One solution is to provide a rotary cutter bar where the outer two or more cutting disks rotate toward the center of the platform to help converge crop into the conditioner opening. Another solution applied to platforms having such rotary cutter bars, for example, is to provide powered crop converging drums either suspended above or mounted directly to one or more of the rotary cutting units disposed along the length of the cutter bar. It is desired that the crop move along in front of the adjacent drums and above the disks as it is moved toward the conditioner opening.
Some such prior art platforms have the disadvantage that crop can get forced underneath suspended converging drums when crop is converging to the discharge zone where the conditioner is located. When crop gets trapped under one or more of the converging drums, further crop can be carried around to the rear of the drum(s) and get trapped between the drum(s) and the bulkhead of the platform. The trapped crop can cause plugging of the drum(s), i.e., the crop can wedge so tight that the drum(s) are prevented from rotating. This can result in the failure of components of the powered drum drive system.
Another drawback of some prior art platform is that crop, particularly that carried by the first cutter disc directly in front of the discharge zone defined between opposite inner side walls to which the conditioner is mounted, will sometimes hairpin on the fronts of these inner side walls. This crop build-up can grow in size until it interferes with crop flow or causes plugging of the converging drums.
To address the drawbacks of the aforementioned converging arrangements, it is known in the art to provide an ejector plate mounted directly to one of the rotary cutting units on the cutter bar to mitigate crop build-up, wrapping and hairpinning. It is also known to use such an ejector plate in combination with a converging drum mounted to the cutting disk on the cutter bar. However, one drawback of such converging arrangements utilizing ejector plates mounted to the cutter bar is that crop build-up, wrapping and hairpinning may not be adequately prevented—especially for more challenging crop and forage processing operations, because the cut material is not sufficiently transferred to the discharge zone.